X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from willowsprings.uwyo.edu ([129.72.10.31] verified) by logan.com (CommuniGate Pro SMTP 5.4c2o) with ESMTPS id 4884593 for flyrotary@lancaironline.net; Sun, 27 Feb 2011 20:19:12 -0500 Received-SPF: none receiver=logan.com; client-ip=129.72.10.31; envelope-from=SBoese@uwyo.edu Received: from ponyexpress-ht1.uwyo.edu (ponyexpress-ht1.uwyo.edu [10.84.60.208]) by willowsprings.uwyo.edu (8.14.4/8.14.4) with ESMTP id p1S1IWKC012103 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL) for ; Sun, 27 Feb 2011 18:18:33 -0700 (MST) (envelope-from SBoese@uwyo.edu) Received: from ponyexpress-mb5.uwyo.edu ([fe80::9813:248c:2d68:a28b]) by ponyexpress-ht1 ([10.84.60.208]) with mapi; Sun, 27 Feb 2011 18:18:32 -0700 From: "Steven W. Boese" To: Rotary motors in aircraft Date: Sun, 27 Feb 2011 18:18:19 -0700 Subject: RE: [FlyRotary] Re: EC2/ Tracy Thread-Topic: [FlyRotary] Re: EC2/ Tracy Thread-Index: AcvWxDrAOiEwylr/S+i4up/+4a8xqwAGO0Aw Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_E1AA3B1AF41D8049B1E3FBD5E225626008872D236Bponyexpressmb_" MIME-Version: 1.0 --_000_E1AA3B1AF41D8049B1E3FBD5E225626008872D236Bponyexpressmb_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Brian, If mode 4 is at the default setting and the engine ran smoothly on just the= secondary injectors when using the backup procedure, it seems unlikely tha= t there is a significant difference in flow rate between those secondary in= jectors. It might be useful to set modes 1, 4, and 6 back to factory defaults and se= t mode 3 at a MAP just below the staging threshold. The reason for this su= ggestion is because when MAP becomes higher than the staging threshold, the= re is the effect of the mixture going lean due to injector lag. There is a= lso the effect of the mixture going rich due to bringing on the larger flow= rate secondary injectors. It just so happens that with 28 lb primaries an= d 40 lb secondaries, these two effects very nearly cancel each other out if= the engine is running in the neighborhood of 4000 RPM and using about 6 ga= l/hr. With a default table and higher fuel flow rates than 6 gal/hr, the i= njector lag effect will gradually tend to make the mixture richer. The exc= ess fuel flow rate will be about 10% by the time a flow rate of around 14 g= al/hr is reached. This richening tendency can then be compensated for usin= g mode 1 or 9. No guarantees, but it may be worth a try. Do you happen to know at what RPM staging occurs on the ground and in fligh= t? Do you also know the fuel flow rates under those two conditions? Steve Boese From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beh= alf Of bktrub@aol.com Sent: Sunday, February 27, 2011 2:20 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: EC2/ Tracy No, I don't have a secondary injector failure as far as I know. Several poi= nts- I had the injectors cleaned and flow tested. Primaries are 28 #, secon= daries 40#- the engine is a 13bREW- 93 twin turbo, but normally aspirated. I checked to see if all= the injectors were firing by disconnecting all the other leads and running= on mode 1, engine off and press program switch. They all are firing. Also = ran the injector backup proceedure. The engine runs well on the ground all through the power band, but in the a= ir , after staging it is a bit rough and misses. My theory- the secondaries= are not firing equally and need to be tuned in mode 4. The engine stages n= ormally at MAP address 84, and transistions through that point pretty smoot= hly, and runs very smooth below that point. That's why I think I need a bit= of rotor matching in mode 4 above the staging point using the EGTs. I feel that I am making definate progress. Brian Trubee --_000_E1AA3B1AF41D8049B1E3FBD5E225626008872D236Bponyexpressmb_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Brian,

 

If mode 4 is at the defau= lt setting and the engine ran smoothly on just the secondary injectors when= using the backup procedure, it seems unlikely that there is a significant = difference in flow rate between those secondary injectors.

 

It might be useful to set mo= des 1, 4, and 6 back to factory defaults and set mode 3 at a MAP just below= the staging threshold.  The reason for this suggestion is because whe= n MAP becomes higher than the staging threshold, there is the effect of the= mixture going lean due to injector lag.  There is also the effect of = the mixture going rich due to bringing on the larger flow rate secondary in= jectors.  It just so happens that with 28 lb primaries and 40 lb secon= daries, these two effects very nearly cancel each other out if the engine i= s running in the neighborhood of 4000 RPM and using about 6 gal/hr.  W= ith a default table and higher fuel flow rates than 6 gal/hr, the injector = lag effect will gradually tend to make the mixture richer.  The excess= fuel flow rate will be about 10% by the time a flow rate of around 14 gal/= hr is reached.  This richening tendency can then be compensated for us= ing mode 1 or 9.  No guarantees, but it may be worth a try. 

 

<= span style=3D'font-family:"Arial","sans-serif";color:black'>Do you happen t= o know at what RPM staging occurs on the ground and in flight?   = Do you also know the fuel flow rates under those two conditions? 

 

<= span style=3D'font-family:"Arial","sans-serif";color:black'>Steve Boese&nbs= p;  

 

 

Fr= om: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On= Behalf Of bktrub@aol.com
Sent: Sunday, February 27, 2011 2:2= 0 PM
To: Rotary motors in aircraft
Subject: [FlyRotary]= Re: EC2/ Tracy

 =

No, I don't have a secondary injecto= r failure as far as I know. Several points- I had the injectors cleaned and= flow tested. Primaries are 28 #, secondaries 40#- the engine

is a 13bREW- 93 twin turbo, but = normally aspirated. I checked to see if all the injectors were firing by di= sconnecting all the other leads and running on mode 1, engine off and press= program switch. They all are firing. Also ran the injector backup pro= ceedure.

 

The engine runs well= on the ground all through the power band, but in the air , after staging i= t is a bit rough and misses. My theory- the secondaries are not firing equa= lly and need to be tuned in mode 4. The engine stages normally at MAP addre= ss 84, and transistions through that point pretty smoothly, and runs very s= mooth below that point. That's why I think I need a bit of rotor matching i= n mode 4 above the staging point using the EGTs.

 

I feel that I am making definate progress.

 

Brian Trubee

=

= --_000_E1AA3B1AF41D8049B1E3FBD5E225626008872D236Bponyexpressmb_--